Abstract

We provide an overview of developments in the use OCT imaging for the detection of retinal
ganglion cell damage in vivo that avoid use of any exogenous ligands to label cells. The
method employs high resolution OCT using broad spectral light sources to deliver axial
resolution of under 5 microns. The resolution approximates that of cellular organelles, which
undergo degenerative changes that progress to apoptosis as a result of axon damage. These
degenerative changes are manifest as the loss of retinal ganglion cell dendrites and
fragmentation of the subcellular network of organelles, in particular, the mitochondria that
support dendritic structure.
These changes can alter the light scattering behaviour of degenerating neurons. Using OCT
imaging techniques to identify these signals in cultured neurons, we have demonstrated
changes in cultured cells and in retinal explants. Pilot studies in human glaucoma suggest
that similar changes are detectable in the clinical setting.
High resolution OCT can be used to detect optical scatter signals that derive from the retinal
ganglion cell layer and are associated with neuronal damage. These findings suggest that
OCT instruments can be used to derive quantitative measurements of retinal ganglion cell
damage. Critically, these signals can be detected at an early stage of retinal ganglion cell
degeneration when cells could be protected or remodeled to support visual recovery.